Studded footwear

ABSTRACT

Apparatus for providing gripping studs in footwear, particularly where such apparatus is utilized on very hard surfaces such as sun baked ground, packed snow or ice. The studs are completely contained within the bottom structure of the footwear to reduce the probability of damage or injury being caused thereby when the footwear is not in use. An elastic material is utilized for the bottom structure which therefore compresses to concentrate the loads on the studs when the footwear is in use. Edges are disposed as the penetrating surface on each stud to facilitate penetration of the walking surface and to maximize the gripping surface developed for very small penetrations. Various stud configurations and arrangements are provided to orient the gripping surface in accordance with the needs of differing applications. To minimize the weight of the footwear and maximize its flexure, arcuately shaped bands are utilized for retaining the studs within the footwear.

United States Patent 1 J ankauskas STUDDED FOOTWEAR [76] Inventor: Joseph G. Jankauskas, 191 Division Ave., Shelton, Conn.

[22] Filed: Apr. 10, 1972 [21] Appl. No.: 242,617

Ohashi Primary Examiner-Patrick D. Lawson Attamey-Armand Cifelli et al.

Rice 36/61 [451 July 24, 1973 [57] ABSTRACT Apparatus for providing gripping studs in footwear, particularly where such apparatus is utilized on very hard surfaces such as sun baked ground, packed snow or ice. The studs are completely contained within the bottom structure of the footwear to reduce the probability of damage or injury being caused thereby when the footwear is not in use. An elastic material is utilized for the bottom structure which therefore compresses to concentrate the loads on the studs when the footwear is in use. Edges are disposed as the penetrating surface on each stud to facilitate penetration of the walking surface and to maximize the gripping surface developed for very small penetrations. Various stud configurations and arrangements are provided to orient the gripping surface in accordance with the needs of differing applications. To minimize the weight of the footwear and maximize its flexure, arcuately shaped bands are utilized for retaining the studs within the footwear.

10 Claims, 8 Drawing Figures 1 STUDDED FOOTWEAR BACKGROUND OF THE INVENTION The present invention relates to footwear having gripping studs, especially where such footwear is im tended for use on very hard surfaces. Hitherto, many different devices have been used to improve the gripping capability of footwear. Vacuum producing grips are used where the walking surface is smooth and nonporous, however, sun baked ground or packed snow and ice covered walkways rarely present these conditions and therefore, vacuum grips are notidealy suited for such walking surfaces. Where very hard and irregular surfaces are encountered, penetrating studs mustbe utilized which develop the largest possible gripping surface upon penetrating the walking surface to a very small depth.

In most studded footwear, the studs are disposed to protrude from the bottom structure of the footwear at all times. When such footwear is not in use, the studs therefore present a safety hazard and. have been known to inadvertently scratch floors and furniture or cut human skin. 1

In some studded footwear, the studs develop a gripping surface of sufficientmagnitude only after'considerable penetration into the walking surface. Therefore,

each stud is configured to have a single conical or contoured member which presents a very small penetrating surface against the walking surface to facilitate penetration thereof. On very hard walkingsurfaces, the penetration of such studs is drastically reduced and therefore, the magnitude of the gripping surface developed is insufficient. Although the depth of penetration for any stud configuration will be reduced on very hard walking surfaces, the ratio of gripping surface developed to penetrating surface presented'will bethe greatest for a stud configuredtopresent anedgeas the penetrating surface. This is so because an edge has the greatest periphery to area ratio and the gripping surface developed is directly proportional to both the depth of penetration and the periphery of the penetrating surface.

In other studded footwear, studs having penetrating edges are utilized, however, the gripping surface developed thereby is not of consistent magnitude in all directions. Therefore, the gripping forces generated against the gripping surface is not of consequence in all directions. Such studs are particularly inappropriate for use on packed snow or ice covered walkingsurfaces where the capability to generate gripping forces must exist in all directions.

In still other studded footwear, thestudsaresecured to the footwear by means of a rigid plate. This plate limits the flexure characteristics'of the footwear and causes it to be quite heavy, which therefore renders the footwear unacceptable for casual use.

SUMMARY OF THE INVENTION and to develop a relatively large gripping surface for a relatively minor penetration.

It is another object of the present invention to provide footwear having studs which are configured to develop a gripping surface having a directional distribution in accordance with the application.

It is still another object of the present invention Ito provide footwear having gripping studs which are s'ecured within the footwear between bands of relatively low weight and high flexibility.

These objects are accomplished in one form according to the present invention by completely containing all studswithin the footwears bottom structure which is constructed of an elastic material. Each stud is con- I figured to have a plurality of penetrating legs and each BRIEF DESCRIPTION OF THE DRAWING The manner in which these and other objects of the invention are achieved will best be understood by reference. to the following description, the appended claims,

' and the Figures of the attached drawing wherein:

vide footwear having gripping studs which protrude only' when the footwear is in use.

It is a more specific object of the present invention to provide footwear having studs which are configured to facilitate penetration of very hard walking surfaces FIG. 1 is aside elevational view of footwear embodying thisinvention and having portions thereof cut away to illustrate the disposition of a gripping stud therein;

FIG. 2 is a partial bottom view thereof illustrating the edges presented by the studs for penetration of the walking surface;

FIG. 3 is an enlarged sectional view thereof taken substantially along line 3-3 of FIG. 1 to illustrate the disposition of the collar within the footwear;

FIG. 4 is an enlargedperspective view of the collar on which thestuds are affixed to arcuate bands;

FIG. 5 is a partial transverse section of the footwear taken substantially along line 5-5 of FIG. 3 and illustrating the use of the footwear on a very hard and irregular walking surface;

FIG. 6 is a perspective view of a gripping stud which develops a gripping surface of relatively consistent magnitude in all directions upon uniform penetration into the walking surface;

FIG. 7 is a perspective view of a gripping stud which develops a maximum gripping surface in either direction along a line perpendicular to the edges upon penetration into the walking surface; and

FIG. 8 is a perspective view of a gripping stud on which ridges are disposed to develop a gripping surface having a directional distribution in accordance with the application of the footwear.

DESCRIPTION or THE PREFERRED EMBODIMENT Turning now to the drawings, studded footwear l0 incorporating the improvements of this invention, is illustrated in FIGS. 1 3. As is conventional, the foot- Wear 10 has abody 12 attached to a bottom structure 14 which includes both a sole 16 and a heel 18. Gripping studs 20 are retained within the bottom structure 14 to generate grippingforces parallel to a walking surface 22 and thereby supplement the traction developed by the footwear 10 against the walking surface 22, as illustrated in FIG. 5. The bottom structure 14 is made of elastic material and develops traction through a bearing surface 24 which contacts the walking surface 22. All of the studs are disposed to be flush with the bearing surface 24 and are retained as part of a collar 26 which is affixed within the bottom structure 14 by suitable means. One such means is to mold the collar 26 integrally into the bottom structure 14. Although the studs 20 are shown only in the heel 18, no reason is known to preclude a similar installation of studs 20 into the sole 16.

The collar 26 is constructed of arcuate bands 28 between which the studs 20 are secured, as illustrated in FIGS. 2 4. Each stud 20 has two legs 30 protruding from a base 32, as illustrated in FIG. 6. The base 32 joins to the arcuate bands 28, as illustrated in FIG. 4, and the legs 30 extend to the bearing surface 24 of the bottom structure 14, as shown in FIG. 3. Each leg 30 is tapered to an edge 34 and is disposed perpendicularly to the other leg 30. The studs 20 are made of very rigid material which is also suited for conditions of abrasive wear. Many metals and some plastics comply with these criteria and although it is not absolutely necessary to do so, the arcuate bands 28 can be made of the same material as the studs 20. Any suitable means may be utilized for joining the studs 20 to the arcuate bands 28 and where a similarity exists between their materials, they can be welded together or integrally cast in a single piece.

Gripping forces are only generated by the studs 20 after they have penetrated the walking surface 22 to thereby develop a gripping surface 36, as illustrated in FIG. 5. In penetrating the walking surface 22, each stud 20 presents a penetrating surface 38 over which the load on the stud 20 is distributed perpendicularly to the walking surface 22. The magnitude of the gripping force generated is directly proportional to the area of the gripping surface 36 which in turn is directly proportional to both the depth of penetration and the projected length of the penetrating surface 38 perpendicular to the direction of the gripping force. Where the walking surface 22 is very hard, as would be the case for sun baked ground, packed snow or ice, the depth of penetration for any stud 20 is inversely proportional to the magnitude of its penetrating surface 38. Therefore, to maximize the gripping force generated in a particular direction, the penetrating surface 38 on the stud 20 must be minimized while the projected length of the penetrating surface 38 perpendicular to that direction must be maximized. These optimal conditions are attained when an edge is utilized as the penetrating surface and therefore the edges 34 of the studs 20 are disposed flush with the bearing surface 24, as illustrated in FIG. 3. Upon penetration of each edge 34 a maximum gripping force will be generated in either direction along a line perpendicular to the edge 34 and a negligible gripping force will be generated in either direction along a line parallel to the edge 34. Therefore, to generate a relatively consistent gripping force in all directions upon uniform penetration of each stud 20, the edges 34 on each stud 20 are disposed perpendicularly to each other, as illustrated in FIG. 6.

Applications do exist where it is desirable to generate a maximum gripping force in a single direction. A stud 20' for such applications is illustrated in FIG. 7 where due to the similarities existing with the stud 20 of FIG. 6, similar parts are identified by the same reference numerals but with a prime added. The legs 30' of the stud 20' are disposed parallel to each other but present a penetrating surface 38' having the identical magnitude to that of the stud 20 in FIG. 6. Therefore, with the same load applied, the depth of penetration will be the same for both studs 20 and 20, but the gripping force generated perpendicularly to the edges 34' of stud 20' will be twice the gripping force generated perpendicularly to either edge 34 of stud 20. However, the gripping force developed parallel to the edges 34' of stud 20 will be negligible whereas stud 20 develops a gripping force of relatively consistent magnitude in all directions upon uniform penetration into the walking surface 22. It should also be recognized that a plurality of studs 20' can be distributed across the bottom structure 14 of the footwear 10 in an alignment to develop a cumulative gripping force of relatively consistent magnitude in any direction upon uniform penetration of the studs 20'.

Where studs having tapered legs are undesirable due to either structural or manufacturing limitations, studs 20" having blunt legs, such as those illustrated in FIG. 8, may be utilized. Due to the similarities existing with the stud 20 of FIG. 6, similar parts in FIG. 8 are identifled by the same reference numerals as those used in FIG. 6 but with a double prime added. Although the penetrating surface 38" presented by the blunt terminations of the legs 30" would normally be much too large for developing a gripping surface 36" of any consequence, ridges 40 are disposed on the blunt faces of each leg 30". Each ridge 40 presents an edge 34" and the ridges 40 can be oriented to align the edges 34" in any relative direction in developing a gripping surface 36" having a directional distribution in accordance with the application. For example the edges 34" could all be aligned in a specific direction to achieve the same .result as achieved with stud 20 of FIG. 7 or they could be aligned with alternate perpendicularity to achieve the same result as achieved with stud 20 of FIG. 6.

When the footwear 10 is in use, the bearing surface 24 of the bottom structure 14 contacts the walking surface 22 to distribute the applied load, as illustrated in FIG. 5. The applied load causes the elastic material to compress and retract from around the studs 20, which thereby results in concentrating the applied load on the rigid studs 20. Due to the very small penetrating surfaces 38 presented by the edges 34 of the studs 20, the pressure developed against the walking surface 22 from the applied load is very large and therefore, the edges 34 penetrate into the walking surface 22 to some depth. As each stud 20 penetrates the walking surface 22, gripping surfaces 36 develop from each edge 34. The magnitude of each gripping surface 36 developed is equal to the length of the edge 34 multiplied by the depth of penetration. Each gripping surface 36 developed is then available to generate a gripping force against the substance of the walking surface 22. Where the walking surface 22 is irregular, as illustrated in FIG. 5, the studs 20 will not penetrate the walking surface 22 uniformly, however, the applied load will be distributed over less bearing surface 24. This causes the bot tom structure 14 to compress more and further concentrates the applied load on fewer studs 20 which thereby causes those studs to penetrate to a greater depth.

Aside from locating the studs 20 within the bottom structure 14, the collar 26 serves to distribute the cumulative load from the studs 20 to the bottom structure 14. In most studded footwear this distribution is accomplished through a solid plate which increases the weight of the footwear to a much greater degree than does the collar 26. It is also true, that the bands 28 of the collar 26 are much more flexible than a solid plate and therefore provide more comfort in footwear when utilized to retain studs 20 in locations where flexure occurs, such as the sole 16 of the footwear 10. However, the bands 28 of the collar 26 distribute the load over less area and where the material of the bottom structure 14 is highly elastic, the collar 26 may be forced to embed further into the bottom structure 14 when loads are applied. Where such a problem exists, the bottom structure 14 may be fabricated in layers. A relatively rigid layer would be disposed between the body 12 of the footwear l0 and the collar 26 whereas a relatively spongy layer would be disposed between the rigid layer and the bearing surface 24.

When the footwear is not in use, no load is exerted on the bearing surface 24 and therefore the studs 20 remain completely contained within the bottom structure 14. In this disposition, the studs 20 present little possibility of inadvertently causing bodily injury or damage 'to property. In conventional studded footwear, the

studs protrude regardless of whether or not the footwear is in use and therefore the possibility that such footwear will scratch floors, nick furniture or cut human skin exists at all times.

It should be readily appreciated by those skilled in this art that the studded footwear embodied by this invention provides for studs which protrude only when the footwear is in use. Also, the studs are configured to penetrate very hard walking surfaces, to develop a relatively large gripping surface upon relatively minor penetration of the walking surface, and to distribute the gripping surface developed in accordance with the directional requirements of the footwears application. Furthermore, the studs are incorporated into the footwear with a relatively small increase in weight and a relatively minor reduction in flexure characteristics.

It should be understood that the present disclosure has been made only by way of example and that numerous changes in details of construction and the combination or arrangement of parts may be resorted to without departing from the true spirit and scope of the invention, and therefore, the present disclosure should be construed as illustrative rather than limiting.

What I claim is:

1. ln footwear apparatus of the type wherein applied loads on said footwear are distributed upon the walking surface through a bottom structure and wherein gripping forces are generated with a plurality of rigid studs protruding from said bottom structure, the improvement comprising:

said studs being completely contained within said bottom structure, said bottom structure being constructed of an elastic material, said elastic material being compressed by the applied loads on said footwear to retract from around said studs and thereby concentrate the applied loads on said studs.

2. In the combination of claim 1 wherein each said stud presents a penetrating surface in contact with the walking surface, said penetrating surface being an edge and wherein a gripping surface develops upon penetration of said edge into the walking surface, said gripping surface generating a gripping force against the substance of the walking surface, said gripping force being of maximum magnitude in either direction along a line perpendicular to said gripping surface, said studs being distributed across said bottom structure in relative alignment to develop said gripping forces in accordance with the application of said footwear.

3. In the combination of claim 2 wherein each said stud includes a plurality of legs, each said leg being tapered to an edge, each said edge being a portion of said penetrating surface.

4. In the combination of claim 3 wherein each said leg is disposed perpendicularly to another said leg, said stud developing said gripping forces of relatively consistent magnitudes in any direction parallel to the walking surface upon uniform penetration of said stud into the walking surface.

5. In the combination of claim 3 wherein each said leg is disposed parallel to all other said legs, said stud developing a maximum gripping force in either direction along a line perpendicular to said edges.

6. In the combination of claim 2 wherein each said stud includes a plurality of legs, each said leg being terminated with a blunt face and wherein ridges are disposed on. each blunt face, each said ridge having an edge, each said edge being a portion of said penetrating surface.

7. In the combination of claim 6 wherein each said ridge is disposed perpendicularly to another said ridge, said stud developing said gripping forces of relatively consistent magnitudes in any direction parallel to the walking surface upon uniform penetration of said stud into the walking surface.

8. In the combination of claim 6 wherein each said ridge is disposed parallel to all other said ridges, said stud developing a maximum gripping force in either direction along a line perpendicular to said ridges.

9. In the combination of claim 1 wherein said studs are affixed between arcuate bands, said bands being relatively more flexible and of relatively less weight than a solid plate.

10. In the combination of claim 9 wherein each said stud presents a penetrating surface in contact with the walking surface, said penetrating surface being an edge and wherein a gripping surface develops upon penetration of said edge into the walking surface, said gripping surface generating a gripping force against the substance of the walking surface, said gripping force being of maximum magnitude in either direction along a line perpendicular to said gripping surface, said studs being distributed across said bottom structure in relative alignment to develop said gripping forces in accor- 

1. In footwear apparatus of the type wherein applied loads on said footwear are distributed upon the walking surface through a bottom structure and wherein gripping forces are generated with a plurality of rigid studs protruding from said bottom structure, the improvement comprising: said studs being completely contained within said bottom structure, said bottom structure being constructed of an elastic material, said elastic material being compressed by the applied loads on said footwear to retract from around said studs and thereby concentrate the applied loads on said studs.
 2. In the combination of claim 1 wherein each said stud presents a penetrating surface in contact with the walking surface, said penetrating surface being an edge and wherein a gripping surface develops upon penetration of said edge into the walking surface, said gripping surface generating a gripping force against the substance of the walking surface, said gripping force being of maximum magnitude in either direction along a line perpendicular to said gripping surface, said studs being distributed across said bottom structure in relative alignment to develop said gripping forces in accordance with the application of said footwear.
 3. In the combination of claim 2 wherein each said stud includes a plurality of legs, each said leg being tapered to an edge, each said edge being a portion of said penetrating surface.
 4. In the combination of claim 3 wherein each said leg is disposed perpendicularly to another said leg, said stud developing said gripping forces of relatively consistent magnitudes in any direction parallel to the walking surface upon uniform penetration of said stud into the walking surface.
 5. In the combination of claim 3 wherein each said leg is disposed parallel to all other said legs, said stud developing a maximum gripping force in either direction along a line perpendicular to said edges.
 6. In the combination of claim 2 wherein each said stud includes a plurality of legs, each said leg being terminated with a blunt face and wherein ridges are disposed on each blunt face, each said ridge having an edge, each said edge being a portion of said penetrating surface.
 7. In the combination of claim 6 wherein each said ridge is disposed perpendicularly to another said ridge, said stud developing said gripPing forces of relatively consistent magnitudes in any direction parallel to the walking surface upon uniform penetration of said stud into the walking surface.
 8. In the combination of claim 6 wherein each said ridge is disposed parallel to all other said ridges, said stud developing a maximum gripping force in either direction along a line perpendicular to said ridges.
 9. In the combination of claim 1 wherein said studs are affixed between arcuate bands, said bands being relatively more flexible and of relatively less weight than a solid plate.
 10. In the combination of claim 9 wherein each said stud presents a penetrating surface in contact with the walking surface, said penetrating surface being an edge and wherein a gripping surface develops upon penetration of said edge into the walking surface, said gripping surface generating a gripping force against the substance of the walking surface, said gripping force being of maximum magnitude in either direction along a line perpendicular to said gripping surface, said studs being distributed across said bottom structure in relative alignment to develop said gripping forces in accordance with the application of said footwear. 